foo.c:2:1: error: unknown type name 'using'
    2 | using namespace std;
      | ^~~~~
foo.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    2 | using namespace std;
      |                 ^~~
foo.c: In function 'main':
foo.c:5:5: error: unknown type name 'string'; did you mean 'stdin'?
    5 |     string a,g;
      |     ^~~~~~
      |     stdin
foo.c:8:5: error: 'cin' undeclared (first use in this function)
    8 |     cin>>n;
      |     ^~~
foo.c:8:5: note: each undeclared identifier is reported only once for each function it appears in
foo.c:30:5: error: 'cout' undeclared (first use in this function)
   30 |     cout<<g<<endl<<result<<endl<<sum<<endl;
      |     ^~~~
foo.c:30:14: error: 'endl' undeclared (first use in this function)
   30 |     cout<<g<<endl<<result<<endl<<sum<<endl;
      |              ^~~~

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